1. Field of the Invention
The present invention relates to a main cartridge attachable and detachable to and from an electrophotographic image forming apparatus, and a process cartridge. The present invention also relates to an image forming apparatus having the process cartridge.
The electrophotographic image forming apparatuses form an image on a recording medium using an electrophotographic image forming process. The electrophotographic image forming apparatuses include, for example, electrophotographic copying machines, electrophotographic printers (for example, laser beam printers and light-emitting diode (LED) printers), electrophotographic facsimile apparatuses, and electrophotographic word processors.
The recording media on which an image is formed by an electrophotographic image forming apparatus include, for example, paper and overhead projector (OHP) sheets.
The process cartridge is detachably attached to the main body of an electrophotographic image forming apparatus. The process cartridge is provided with at least one process device used in an image forming process for forming an image on a recording medium. The process cartridge and the process device are integrated as a cartridge. The electrophotographic process devices include charging devices, development devices, and cleaning devices.
2. Description of the Related Art
The above-described cartridge is replaced by the user when the user attaches the cartridge to the apparatus main body or when the cartridge reaches its end of life. In the replacement of the cartridge by the user, a grip portion can be provided for the user to surely hold the cartridge. For example, Japanese Patent Application Laid-Open No. 2003-208074 discussed this type of a grip. In Japanese Patent Application Laid-Open No. 2003-208074, in attaching the cartridge to the apparatus body, the user holds the grip portion protruding from a frame body of the cartridge, and inserts the cartridge into the apparatus along a guiding portion of the apparatus body. When the user removes the cartridge from the apparatus body, the user holds the grip portion with hands, and takes it out of the apparatus. The grip portion provided in the cartridge enables the user to easily attach and detach the cartridge to and from the apparatus body.
Further, in a technique discussed in Japanese Patent Application Laid-Open No. 2002-311709, the attachment and detachment directions of a cartridge containing toner is orthogonal to the attachment and detachment directions of a developing unit. In contrast to a mechanism in which the attachment and detachment directions of the toner unit and the development unit are the same, the fixation releasing mechanism of the development unit can be omitted.
The cartridge may be further separated into a plurality of cartridges, and in such cartridges, one cartridge is referred to as a main cartridge and the other cartridge detachably provided to the main cartridge is referred to as a sub cartridge. In Japanese Patent Application Laid-Open No. 2002-311709, the development unit (development cartridge) is the main cartridge, and the toner unit (toner cartridge) is the sub cartridge. Among mechanisms attaching and detaching the sub cartridge in the longitudinal direction of the main cartridge, a case that the grip portion is provided in the whole longitudinal direction of the main cartridge as discussed in Japanese Patent Application Laid-Open No. 2002-311709 is described.
In the case where the grip portion is provided in the whole longitudinal direction of the main cartridge, the portions held by the user vary. Depending on the portions in the grip portion held by the user, the balance in the longitudinal direction can be lost, which makes it hard to grip. Moreover, if the grip portion is provided at a central portion of the main cartridge in the longitudinal direction, when the user attaches the sub cartridge, the distance between the position of the grip portion of the main cartridge and the position of the sub cartridge held by the user increases. As a result, especially in a case of a large cartridge, the attachment and detachment operation of the main cartridge and the sub cartridge can become difficult.